Stock by Attribute v4.0 addon for v1.3.5-1.3.9

[mc12345678]

I want to thank the github user @jodeantn that pointed out an issue with the ZC 1.5.5 file(s) includes/templates/YOUR_TEMPLATE/templates/tpl_checkout_confirmation_default.php and equivalently includes/templates/YOUR_CLASSIC_RESPONSIVE/templates/tpl_checkout_confirmation_default.php. Apparently when arriving at the checkout_confirmation page, an error was generated in the logs folder and the remainder of the page/final checkout was affected. Issue #43 at the github storage location provides some more detail. The error was similar to:

PHP Fatal error: Call to undefined method  payment::process_form_params() in public_html/includes/templates/YOUR_TEMPLATE/templates/tpl_checkout_confirmation_default.php  on line 205 Line 205   echo zen_draw_form('checkout_confirmation',  $form_action_url, 'post', 'id="checkout_confirmation"  onsubmit="submitonce();"' . (is_array($payment_modules->modules) ?  $payment_modules->process_form_params() : ''));

Where YOUR_TEMPLATE would be expected to be the foldername for the active template for the user visiting.

The fix involves removing a portion of code that was incorporated into the SBA provision of the files for ZC 1.5.5 in December 2016, expecting that the PayPal InContext code provided/referenced in the solution would be used/considered. That appears to still be out for debate, but I didn't remove the following snippet until today about 15 minutes ago.

Applicable only to copies that were downloaded sometime between December 18, 2016 and today January 31, 2017:
To fix existing installations/downloads of the ZC 1.5.5 templates (although this code was not specifically marked as being applicable to SBA) then need to modify as applicable both
includes/templates/YOUR_TEMPLATE/templates/tpl_checkout_confirmation_default.php
and
includes/templates/YOUR_CLASSIC_RESPONSIVE/templates/tpl_checkout_confirmation_default.php

and change this: (portion to be removed in red color)

echo zen_draw_form('checkout_confirmation', $form_action_url, 'post', 'id="checkout_confirmation" onsubmit="submitonce();"' . (is_array($payment_modules->modules) ? $payment_modules->process_form_params() : ''));

to this:

echo zen_draw_form('checkout_confirmation', $form_action_url, 'post', 'id="checkout_confirmation" onsubmit="submitonce();"');

See issue #1192 on the ZC github for updates on incorporating the PayPal Incontext code that would be needed to support keeping the file(s) the way they were.